The invention is based upon a chain guide for a control-shaft drive of an internal-combustion engine and upon a method of producing a chain guide. Chain guides for control-shaft drives of internal-combustion engines are known (see for example U.S. Pat. No. 4,832,664 issued to Grxc3x6ger, et al.), in which two bearing lugs are provided in the jaw-shaped chain guide in order to retain the chain guide. Grxc3x6ger discloses using two different materials in construction of chain guides. In particular, Grxc3x6ger discloses using a plastic material such as polyamide for the main body portion and a more wear-resistant material such as polyamide with fiberglass additions for the slide lining portion. In this case the bearing pins engaged in the bearing lugs are mounted on a housing part of the internal-combustion engine and hold the chain drive in the desired position with respect to the control chain. Because of the limited space inside the control-chain housing of an internal-combustion engine it can be extremely difficult in some cases to fasten chain guides of this type since the accessibility of the fastening points is restricted.
The present invention therefore provides a secure fastening for the chain guide in the control-chain housing, which at the same time permits a simple assembly and dismantling of the chain guide.
The chain guide can be fixed in a simple and secure manner in the control-chain housing with the aid of the pin provided on the main body of the chain guide, as the pin of the chain guide engages with positive locking in a recessxe2x80x94suitably adapted to the contour of the pinxe2x80x94in the control-chain housing of the internal-combustion engine. During the assembly of the chain drive or the control-shaft drive, the chain guide can be inserted in a simple mannerxe2x80x94with its end facing the pin firstxe2x80x94between the control chain and the housing from below, i.e. from the crank space, until the pin engages in the recess and is securely fixed by a bearing pin with the aid of the bearing lug provided at the other end of the chain guide. It is also possible for the chain guide to be fastened to the bearing lug thereof before the cylinder-head housing has been assembled, in order to place the cylinder head on the cylinder subsequently, so that the pin can again engage the recess.
The pin for the chain guide can be produced according to the invention in that the covering of the pin is produced together with the slide-lining member for the chain guide in an injection-molding process. In this way, the wear-resistant lining can be applied to the main body and the wear-resistant covering for the pin can be produced in one operation.